Candy is a term for a type of confectionery prepared by dissolving sugar in water or milk and boiling it until it starts to caramelize. The sugar solution is called a syrup. Depending upon the solvent and upon end result of the process the candy may be called candy, caramel, toffee, fudge, praline, or tablet. The recipe also governs how hard, soft, chewy or brittle the end result may be.
The eventual texture of candy depends on the temperature to which the sugar solution is boiled. The presence of a solute, such as sugar, in a liquid tends to elevate the boiling point of the liquid. (See boiling point.) Sugar water therefore boils at a higher temperature than pure water, and the higher the sugar concentration, the higher the boiling point. As the syrup is heated, it boils, and the boiling away of water increases the sugar concentration in the syrup, raising the boiling point still further. The relationship between the boiling point and the sugar concentration is predictable, and so heating the syrup to a particular temperature ensures a particular sugar concentration with some accuracy. In general, higher temperatures (which imply greater sugar concentrations) result in hard, brittle candies, and lower temperatures result in softer candies.
In North America, the word candy is often used as a synonym for the more general term confectionery. In British English, the word candy has become archaic and has only survived in the term "candy floss". When used in the UK, candy is generally taken to mean a sweet, that is any sort of confectionery.
Stages of cooking candy
See also: candy cane